1. Technical Field
The present invention relates to a series of novel heteroaryl carboxamide compounds, the synthesis of these compounds their use in the treatment of inflammatory disease and pharmaceutical compositions comprising these compounds
2. Background Information
RIPK2 (also known as RICK, CARDIAK, CARD3, or RIP2) is a dual specific serine/threonine and tyrosine kinase which is a key component of pro-inflammatory signaling through the NOD1 and NOD2 signaling pathways (Inohara et al. 1998; McCarthy et al. 1998; Thome et al. 1998; Tigno-Aranjuez et al. 2010). The NOD receptors are one of the mechanisms for surveillance for intracellular bacterial pathogens. Bacterial cell wall components initiate signals through the NOD1 and NOD2 pathway by the binding of NOD1 bacteria ligands, D-glutamyl-meso-diaminopimelic acid, and the NOD2 ligand, muramyl dipeptide, to the appropriate intracellular NOD receptors (Girardin et al. 2003a; Girardin et al. 2003b; Girardin et al. 2003c; Chamaillard et al. 2003; Inohara et al. 2003). This binding induces oligomerization of the NOD protein through homotypic CARD/CARD domain interactions (Inohara et al. 2000; Ogura et al. 2001). This activation of NOD receptors leads to Lys63-linked polyubiquitination of RIPK2 through activation of ubiquitin E3 ligases such as XIAP, cIAP1, cIAP2, TRAF2, TRAF5, and TRAF6 (Krieg et al. 2009; Bertrand et al. 2009; Yang et al. 2007; Hasegawa et al. 2008) and recruits the linear ubiquitin system (LUBAC) (Damgaard et al. 2012; Ver Heul et al. 2013). Additionally, RIPK2 undergoes autophosphorylation of Tyrosine474 as part of its activation and assembly into the NOD signaling complex (Tigno-Aranjuez et al. 2010). Further RIPK2, dependent assembly of the signaling complex results in the activation of IKKα/β/γ and TAK1, leading to activation of NF-κB and MAPK pathways resulting in the production of proinflammatory cytokines (Yang et al. 2007).
Mutations in NOD2 have been linked to multiple diseases. Activating mutations have been linked to Early Onset Sarcoidosis (Kanazawa et al., 2005) and Blau syndrome (Miceli-Richard et al., 2001) which affect skin, joints, and eyes. These activating mutations result in increased basal NF-κB activity (Kanazawa et al., 2005). Loss-of-function mutations in the NOD2 LRR are linked to Crohn's Disease (Ogura et al. 2001; Hugot et al. 2001; Hampe et al. 2001; Hampe 2002; Lesange 2002). In addition, polymorphisms in NOD1 have been linked to atopy (Weidinger et al. 2005) and asthma (Hysi et al. 2005). Additional studies in cellular and in vivo mouse models have suggested a role for NOD1 and NOD2 signaling in a variety of diseases such as Graft vs. Host Disease, Arthritis, Multiple Sclerosis, and Diabetic Nephropathy (Peaneck et al. 2009; Saha et al. 2009; Vieira et al. 2012; Rosenzweig et al. 2010; Joosten et al. 2008; Shaw et al. 2011; Du et al. 2013). Small molecule inhibitors of RIP2 kinase (RIPK2) are disclosed in US2013/0023532 A1 but appear to have limited potency.
Pharmacological inhibition of RIPK2 by a potent and selective small molecule inhibitor will attenuate pro-inflammatory signaling through the bacterial sensing pathways initiated by NOD1 and NOD2 stimulation. This reduction in inflammatory signaling will provide therapeutic benefit in a variety of autoinflammatory diseases. Thus, there is a need for potent inhibitors of RIPK2 for pharmaceutical purposes.